Concrete conveyor



CONCRETE CONVEYOR TTOZNEYS Dec. 23, 1969 H. M. ZIMMERMAN 3,485,481

CONCRETE CONVEYOR Filed Feb. 27. 196B s sheets-sheet a /A/VE/vrae, maA44/Paw M. Z/MMf/w/ J EMMG) uw. 2a, 1969 H,M.2.WWM/wl 3,485,481

` CONCRETE ooNvEYoR Filed Feb. 27, 196s 4 s sheets-sheet a ,wwf/woe,Meow /V .mmm/4N United States Patent O 19 Claims ABSTRACT F THEDISCLOSURE There is disclosed a conveyor arrangement for receivingpre-mixed concrete and causing the same to be moved through an outlet sothat the concrete can be delivered to a location remote from theconveyor arrangement. The arrangement is such that it can convenientlytake the form of a trailer unit, although it can be mounted on otherbases. The arrangement incorporates a iluid `motor operated displacementpump and means for receiving the concrete and positively moving the sametoward the displacement pump chamber. Further, the arrangementincorporates valve means cooperatively associated with the displacementpump so as to permit proper filling of the displacement pump chamberwith concrete,` and proper movement of the concrete therefrom.Desirably, such valve means include a valve which seals the` dislacementchamber from the atmosphere while the chamber is lling. Auxiliarycomponents such as an agitating hopper, selfacontained power unit andthe like can be utilized to advantage as part of the arrangement. Inaccordance with the disclosed embodiment, the displacement pump isactuated by a iluid motor supplied with operating fluid under pressuredelivered thereto by a valve controlled uid supply conduit; a by-passconduit communicates with the fluid supply conduit in such a manner thatuid under pressure may be delivered to a rotary fluid motor associatedwith the agitating hopper so that operation of the agitator may becontinued even though the flow of uid through the fluid conduit leadingto the fluid motor for actuating the displacement pump is discontinued.

BACKGROUND OF THE INVENTION The invention relates generally to a pre-mixconcrete conveyor and particularly to a conveyor that is capable ofpumping pre-mixed concrete from a self-contained pre-mix producing unitor a pre-mix delivery truck directly to a remote point of use, such as abuilding construction form.

It is well known that among the problems that building contractors facetoday are labor shortages, the high cost of labor and the high cost ofequipment necessary to transport pre-mixed concrete from aself-contained concrete producer unit or a concrete delivery truck to aremote point of use. Thus, the need for a practical and profitabledevice to convey concrete from the mixer to the form is apparent. Forexample, extensive investigation shows that pumping concrete from amixer to a form can reduce the cost of this operation by about 35percent and that concrete pumping is practical at more than one-third ofall pours. Concrete pumping is both practical and profitable where itcan replace manpower, where ICC it can replace ramps, bridges, hoists,etc., where job evaluation shows concrete can be placed faster and atless costs than by other methods, and with many `special pours such assewers, tunnel linings, etc; t

The low cost of the present development, which is about half that of thelarger pumps now on the market, makes it a practical investment whenused as a single unit or in multiples of single units. With multipleunits, it is practical to operate them (l) teamed together to equal orexceed the capacity of larger units; (2) teamed in relay to extendhorizontal and/or vertical delivery distance; (3) to operate them inteams to assure continuing delivery without stoppage (cold jointprevention); and (4) maximum dependability. g

Taking into consideration the foregoing problems, it is the primaryobject of the present invention to entirely eliminate these problems, orat least, to reduce them to a minimum.

Another Object of the invention is vto provide a premix concreteconveyor having a capacity just suilcient to keep an average handlingnishing crew continuously busy.

Yet another object of the invention is to provide a concrete mixconveyor of such a size and weight that it can be readily transportedfrom one building site to another. To this end, it may take the form ofa trailer unit. It may, however, be formed as an integral part of aconstruction truck or mounted as an independent unit on a base and thenmounted on a construction truck.

Still another object of the invention is to provide a concrete conveyorin which concrete may be delivered from a concrete pre-mix producingunit or concrete pre-mix supply truck, over substantial distances, toremote points of use without entraining air into the concrete, or atleast, reducing the amount of entraned air to a minimum.

A further object of the invention is to provide a concrete conveyor thatincludes a concrete mix displacement pump, the valves and motor of whichare operated by uid pressure.

A still further object of the invention is to provide a concreteconveyor having a iluid actuated displacement pump and a fluid actuatedconcrete agitator having a common valve controlled uid supply conduit.

Another object of the invention is to provide a concrete conveyorwherein the motor of the displacement pump and the motor of the agitatorare supplied with uid from a valve controlled fluid supply conduit thatincludes a by-pass conduit leading to the motor of the agitator so thatoperation of the agitator may be continued, notwithstanding the factthat ilow of fluid to the fluid motor for operating the concretedisplacement pump has been discontinued.

A further additional object of the invention is to provide a concretedisplacement pump in which certain parts of the pump may be displacedrelative to each other to facilitate cleaning thereof.

A still further additional object of the invention is to provide aconcrete conveyor, according to the teachings of the present invention,that is simple in construction, durable and made of materials ofrelatively low cost.

The invention will be better understood and objects other than those setforth will become apparent, after reading the following detaileddescription thereof.

Such description refers to the annexed drawings presenting preferred andillustrative embodiments of the invention.

In the drawings:

FIGURE l is a longitudinal sectional view of a concrete conveyor inaccordance with the present invention;

FIGURE 2 is an end view thereof;

FIGURE 3 is a perspective view of a concrete conveyor showing a portionthereof swung to a position to permit cleaning thereof;

FIGURE 4 is a diagrammatic view showing the fluid conduit system foroperating the fluid motors thereof;

FIGURE 5 is a view, partly in section, showing a motor control valve ina neutral position;

FIGURE 6 is a view, partly in section, showing a motor control valve inone operative position;

FIGURE 7 is a view, partly in section, showing a motor control valve inanother operative position;

FIGURE 8 is a perspective view of a concrete conveyor in accordance withthe present invention mounted on a trailer unit.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, it isto be noted that FIG- URE 8 discloses a self-contained concrete conveyor2 mounted on a trailer 4 and having wheels 6 and a trailer hitch 8. Theconcrete conveyor 2 includes a trap chamber unit 10 that is taperedtoward an outlet end 12. The trap chamber 10 is provided with alaterally extending inlet 14 adjacent its opposite end 16. The end 16 ofthe trap chamber 10 is provided with a flange 18 to which a flange of apump or displacement cylinder 22 is attached in any conventional manner.A trap inlet chamber 24 has one of its ends 26 secured to and incommunication with the lateral inlet 14. The opposite end 28 of the trapinlet chamber 24 is open at 30 to the atmosphere. The trap inlet chamberis also provided with a lateral opening 32 in communication with anopening 34 formed in the end wall 36 of a concrete mix receiver 38.Concrete mix receiver 38 is open at its top 40 and provided with aclosed bottom at 42. A feed screw or auger 44 is mounted adjacent thebottom 42 of the concrete mix receiver 38 by means of bearings 46, 48. Arotary fluid motor 50, mounted adjacent end wall 52, is operativelyattached to the feed screw or auger 44 in such a manner that, onrotation of the feed screw or auger 44, concrete is fed thereby throughopenings 34 and 32 into trap inlet chamber 24. A dump hopper 54, havingan open top 56, is mounted by means of bearings 58, 60 for pivotalmovement above concrete mix receiver 38. Dump hopper 54 is provided witha handle 62 by means of which it may be inverted and its contents dumpedinto the concrete mix receiver 38. An agitator shaft 64 is mounted forrotation within dump hopper 54 and it is provided with a plurality ofagitating paddles 66. A gear 63 is secured to the shaft of the feedscrew or auger 44 and a similar gear `65 is secured to agitator shaft64. An endless chain 67 extends around gears 63 and 65 so that onrotation of the feed screw or auger 44 the agitator paddles 66 are alsorotated.

A pumping or displacement plunger 68 is mounted for reciprocating orsliding movement within pump or displacement cylinder 22. A iluid motor70 comprising a cylinder 72 and piston 74, slidable in cylinder 72, ismounted on the end wall 76 of pump or displacement cylinder 22. A pistonrod 78 is arranged to connect pumping or displacement plunger 68 withthe piston 74 of fluid motor 70.

Pumping or displacement plunger 68 is provided in its periphery with acircumferential groove 80 into which a plurality of O-rings 82, formedof any well known sealing or packing material, are inserted. The forwardface of pump or displacement plunger 68 is provided with a layer ofTellon or rubber 86 to prevent build-up of solid concrete mix on theforward face 84 of displacement plunger 68.

In FIGURE 3 of the drawings, the trap chamber 10 is shown with itsflange 18 spaced from flange 20 which is associated with thedisplacement plunger cylinder 22 that is provided with supporting legs88.

A pair of cooperating gate valve seat members 90, 92 are providedadjacent the outlet end of trap inlet chamber 24. Slidably mountedbetween the cooperating gate valve seat members 90, 92 is a horizontallydisposed gate valve member 94. Gate valve member 94 is connected bymeans of a fork 96 and connecting rod 98 to a double acting fluidactuated motor 100. A vertically disposed gate valve 102 is mountedbetween the outlet end 12 of trap chamber unit 10 and concrete mixdelivery conduit 104. Gate valve 102 is arranged to be moved between itsopen and closing positions by means of a fork 106 and connecting rod 108attached to a double acting fluid actuated motor 110. A horizontallydisposed frame 112 which is integral with, or otherwise secured to, thetrap chamber 10 is arranged to support double acting fluid motor 100. Asimilarly arranged vertically disposed frame 113 is formed integralwith, or otherwise secured to, trap chamber 10 and supports the doubleacting uid motor 110 that is associated with gate valve 102.

A valve 114 is arranged to be pivotally mounted at 116 within theinterior of trap inlet chamber 24. Valve 114 is arranged to seat bygravity on a seating surface 118 formed adjacent the upper edge oflateral opening 32. Pivotally mounted valve 114 when seated on seatingsurface 118 precludes, or at least materially reduces, the entrance ofair into trap chamber 10 when pumping or displacement plunger 68 isretracted in cylinder 22 `by the fluid actuated piston 74.

In FIGURE 4, there is diagrammatically illustrated a iluid system forsupplying fluid to an exhausting fluid from the several double actingfluid motors 70, and 110. A pump 128, of any conventional design, isarranged to draw fluid from storage reservoir 120 by means of conduits112, 126 and lilter 124 and deliver same to a fluid conduit 130 whichleads to a reciprocating fluid motor supply and exhaust valve indicatedgenerally by the reference character Y. A relief valve 132 is providedin fluid conduit 130. Relief valve 132 may be of any conventional typeand may be lset to relieve pressures in excess of any predeterminedvalue. The fluid under pressure which is released by the excess pressurerelief valve 132 is returned by conduit 137 to the storage reservoir120. Motor supply and exhaust valve Y is provided with an operatinghandle 134 and when the valve is in its neutral position, the handle ispositioned as illustrated by the full line circle 136. This position ofthe valve Y corresponds to the position of the valve illustrated in FIG-URE 5 of the drawings. From the position of the valve as indicated bythe position of handle 134, the valve may be pushed to the positionindicated at 138 in FIGURE 4 which corresponds to the position shown inFIGURE 6 of the drawings. Likewise, from the position 136 of the valveas indicated by the handle 134 in FIGURE 4, the valve handle may bepulled to the position 140 which corresponds to the position of themotor supply and exhaust valve as illustrated in FIGURE 7 of thedrawings.

In the position of the motor supply and exhaust valve Y ilustrated inFIGURE 5, the valve lands 154 and 156 uncover the fluid inlet passages142, 144 which connect with the supply conduit 130 so that fluid underpressure may pass through the supply and exhaust valve to the motorcontrol conduits 146 and 148 and land 152 closes the port leading to thereturn passage 150. When fluid under pressure is supplied simultaneouslyto both conduits 146 and 148 by the valve Y, it wil also be supplied toconduits 158, 160, 162 and 164, and, accordingly, to both sides of eachpiston in the double acting lluid motors 100, 110. The lluid pressureacting on each side of the piston in cylinder 110 will then be balancedas will be the pressure on each side of the piston in cylinder 100. Withsuch a balance of the pressures acting on the pistons in cylinder 100and 110, the position of the inlet gate valve 94 and outlet gate valve102 will remain unchanged.

When the handle 134 of the supply and exhaust valve Y is moved to theposition 138 as shown in FIGURE 4, which corresponds to the positionfofthe supply and exhaust valve as illustrated in FIGURE 6, the valve lands152, 154 and 156 will be moved toward the left, as illustrated in FIGURE6. In this position of the valve Y, the valve land 154 will uncover thepassage 142 and motor conduit 146 will then be in communication withfluid pressure supply conduit 130 Also, communication between motorconduit 146 and exhaust conduit 150 will. be cut oir` by valve land 152.At the same time, valve land 156 will cut off communication betweensupply passage 144 and motor conduit 148 but motor conduit 148, becauseof the position of valve land 152, Wil be in communication with exhaustpassage 150. When uid under pressure is supplied to the motor conduit146 and exhausted from motor conduit 148, pressure fluid will besupplied to one side of the lluid motors 100 and 110 in such a mannerthat the inlet gate valve 94 to the trap chamber will be opened and theoutlet gate valve 102 from the trap chamber will be closed.

When the handle 134 of the supply and exhaust valve for the motors 100and 110 is pulled to the position shown at 140 in FIGURE 4, motor supplyand exhaust valve Y will take the position illustrated in FIGURE 7 ofthe drawings, wherein all of the valve lands 152, 154 and 156 have beenmoved to the right. Land 154 will cut off flow of pressure fluid fromsupply passage 142 to motor conduit 146 while valve land 152 openscommunication between motor conduit 146 and exhaust conduit 150. At thesame time, iiuid under pressure in supply conduit 130 will flow throughconduit 144 to motor conduit 148 'while ow of pressure fluid from motorconduit 148 to exhaust conduit 150 is cut off by valve land 152. Withthe motor conduit 148 in communication with the source of pressure uidand the motor conduit 146 in communication with the exhaust conduit 150,the valve motors 100 and 110 will be actuated so as to close the inletgate valve 94 of the trap chamber and to open the outlet gate valve 102of the trap chamber.

The Huid system illustrated in FIGURE 4 is provided with an additionaldouble acting motor supply and exhaust valve designated by the referencecharacter X. Since the construction of the valve X is identical with theconstruction of the valve Y, a detailed description of the valve X isbelieved to be unnecessary. Moreover, reference numerals which apply tothe valve Y likewise apply to the valve X. However, in the case of thevalve X, the reference numerals which relate to similar structuraldetails have been distinguished by providing such numerals with a primedesignation. Thus, when the handle 134 of the motor supply and exhaustvalve X is moved to the position designated 138', pressure fluid willflow from the reservoir 120 through the filter 124 by means of thesupply conduits 122 and 126 to the pump 128. From pump 128 the pressureuid will flow through conduit 130 and a conventional passage in valve Y(not illustrated) to a fluid motor conduit 146 corrected to one side ofcylinder 72 containing uid piston 74.

At the same time, with the handle 134' of the motor supply and exhaustvalve X in the position designated by 136', liuid will ow from thesupply conduit 130, valve X and conduit 148' into the cylinder 72 on theother side of the piston 74. The uid pressure acting on opposite sidesof the piston will then be balanced and the piston 74 and associatedpumping or displacement plunger 68 will remain in the same position. Ifthe motor supply and exhaust valve handle is now moved to the positiondesignated by 138', fluid under pressure will ilow from supply conduit130 through conduit 146', conduit 166, check valve 168 and conduits 170and 172 to the connecting rod end of motor cylinder 72. Meanwhile, theopposite end of the motor cylinder 72, through conduit 148',

valve X and conduit 150 will be in communication with exhaust conduit137 leading to supply reservoir 120. The differential pressure acting onpiston 74 in cylinder 72, through piston rod 78, will cause the pumpingor displacement plunger 68 to be retracted in pump or displacementcylinder 22. Similarly, when the handle 134' of the motor supply andexhaust valve X is moved to the position designated by 134', fluid underpressure will be supplied by the valve X through the conduit 148' to thecylinder 22 on the side of the piston 74 opposite the connecting rod 78,while the opposite end of said cylinder through conduits 172 and 173 wilbe connected to the supply reservoir by way of exhaust conduit 137. Aby-pass conduit 174 is arranged to extend between the supply conduit146' and the fluid conduit 170. A rotary fluid motor 50, which drivesthe feed screw or auger 44, is, preferably, located in by-pass conduit174. The fluid supply conduit which leads to the motor supply andexhaust valves X and Y may, if desired, be provided with a pressuregauge 176 and the fluid conduit 173, downstream of its junction with theconduit 172, may be provided with a shut-olf valve 178.

FIGURES 5 to 7 illustrate an arrangement whereby the supply and exhaustvalves could be actuated by electromagnets 180, 182 instead of handles134, 134', if desired.

When it is desired to make use of the concrete mix conveyor systemherein described, whether it be built as an independent unit that mustbe lifted onto and off a construction truck, a self-powered vehicle ortrailer-mounted, it is transported to a location which is as near aspossible to the point of use or the building construction form intowhich the concrete is to be pouredl but which is still accessible toconcrete supply trucks or another concrete supply source. The concretedelivery conduit 104, which may be formed as a plurality of sections, isthen attached to the end of trap chamber unit 10 and extends to, ornear, the concrete construction form into which the concrete is to bedelivered. l

The handle 134 of valvb Y is then pushed from the position indicated at136 to the position indicated at 138. In this position of the motorsupply and exhaust valve Y, the lands of the valve will be positioned asillustrated in FIGURE 6 of the drawings, with the land 154 positioned topermit flow from the pump 128, conduit 130, supply passage 142 andconduit 146 to motors 100 and 110 to apply pressure to the pistonsthereof in a direction to open gate valve member 94 and close gate valvemember 102. The opposite side of the pistons in motors 100 and 110 willbe connected by conduits 162, 164, 148, 150 and 137 to the fluid storagereservoir 120. Handle 134 of supply and exhaust valve X will then bemoved from the position indicated at 136 to the position indicated atThis will result in a flow of pressure fluid from the pump 128, conduit130, valve Y, valve X and conduits 146', 166, 174, 170 and 172 intomotor cylinder 72 and to apply pressure to the side of piston 74attached to connecting rod 78 while the cylinder adjacent the oppositeside of the piston 74 is exhausted through conduit 148', valve X andconduits 150 and 137 to the fluid supply reservoir 120. The differentialpressure acting on piston 74, through connecting rod 78, will cause thepumping or displacement plunger 68 to be pulled or retracted toward theend of cylinder 22 remote from trap chamber unit 10. Since at this time,gate valve 94 will be open and gate valve member 102 will be closed,concrete will be drawn, with the aid of gravity, from the concrete mixreceiver 24 into pump or displacement cylinder 22 and trap chamber unit10. The handle 134 of the motor supply and exhaust valve Y is then movedto the position indicated as 140. This position of the motor supply andexhaust valve Y corresponds to that illustrated in FIGURE 7. In thisposition of the supply and exhaust valve Y, the lands 152, 154 and 156are positioned so that the flow of pressure.` fluid from pump 128 andconduit 130 to the conduit 146 is prevented by the valve land 154, butflow of pressure fluid from conduit 130 through conduit 144 and valve Yto conduit 148 to the opposite side of the pistons in motor cylinders100 and 110 is made possible. Meanwhile, fluid pressure acting,respectively, on the other faces of the pistons located therein will beexhausted by way of conduits 158, 160, 146, valve Y and conduits 150 and137 tosupply reservoir 120. Upon actuation of the pistons associatedwith motors 100 and 110 in this manner, connecting rods 98 and 108 willreposition gate valves 94 and 102 so that gate valve 94 will be clos/edand gate valve 102 opened. The handle 134 of supply and exhaust valve Xwill then be moved to the position indicated at 138. In this position ofthe supply and exhaust valve X, fluid pressure will be exhausted fromthe side of piston 74 connected to the connecting rod 78 throughconduits 172, 173 and 137 to the supply reservoir 120. Simultaneously,fluid under pressure will be supplied from supply reservoir 120 throughconduit 122, filter 124, conduit 126, pump 128, conduit 130, valve Y,valve X, and conduit 140' to the cylinder 72 so as to apply fluid underpressure to the side of fluid piston 74 opposite to that to which theconnecting rod 78 is attached. The differential in pressure acting onopposite surfaces of piston 74, through connecting rod 78, will causemovement of pumping or displacement plunger 68 in a direction to causedischarge of concrete through the open gate valve 102 into concretedelivery conduit 104. From the delivery conduit 104 the concrete may, ifdesired, be discharged directly into building construction forms.

It will be noted, upon reference to FIGURE 4 of the drawings, by reasonof the provision of a by-pass conduit 173 between conduits 170, 172 andfluid return conduit 137, the operation of rotary motor 50 andassociated feed screw or auger 44 and the mixing paddles 66 on agitatorshaft `64 may be continued even though flow of fluid to the piston foractuating the pump or displacement plunger has been discontinued. If atany time it is desired to discontinue operation of the rotary fluidmotor 50, all that is necessary is to close the shut-off valve 178located in the fluid return conduit 173.

After reading the foregoing detailed description, it will be apparentthat the objects set forth initially have been successfully achieved.Accordingly, what is claimed is:

1. A concrete conveyor system for advancing concrete from a source ofsupply to a selected location comprising a concrete displacement meansincluding a trap chamber unit having an outlet at one end, aninlet-outlet at its other end and an inlet intermediate said outlet andsaid inletoutlet a cylinder secured to said trap chamber unit incommunication with said inlet-outlet; plunger means slidably mounted insaid cylinder for reciprocation within said cylinder; means foreffecting reciprocation of said plunger means; a concrete receiverchamber for supplying concrete to said inlet of said displacement means,said receiver chamber including a first opening in communication withsaid displacement means, a lateral second concrete admission opening forcommunication with a source of concrete and a third atmospheric openinglocated outwardly of said first and second openings; and an outwardlyopening check valve means disposed outwardly of said first and secondopenings and inwardly of said third opening arranged to substantiallypreclude the admission of air through said receiver chamber into saiddisplacement means during a suction Operation of said displacementmeans; inlet valve means associated with said inlet; outlet valve meansassociated with said outlet; first operating means for causing saidinlet valve means to open and close said inlet; second operating meansfor causing said outlet Valve means to open and close said outlet andmeans associated with said first and second valve operating means forcausing said inlet valve means to open the inlet while the outletremains closed and for causing said outlet valve means to open theoutlet while the inlet remains closed.

2. A concrete conveyor system as defined in claim 1 wherein said firstoperating means comprises a first fluid motor means and said secondoperating means comprises a second fluid motor means.

3. A concrete conveyor system as defined in claim 2 wherein each of saidfluid motor means are double acting motors.

4. A concrete conveyor system as defined in claim 3 wherein both of saiddouble acting fluid motors are controlled by a single supply and exhaustvalve means.

5. A concrete conveyor system as defined in claim 1 wherein said meansfor effecting reciprocation of said plunger means is a fluid motormeans.

6. A concrete conveyor system as defined in claim 5 wherein said fluidmotor means for effecting reciprocation of said plunger means is adouble acting fluid motor means.

7. A concrete conveyor system as defined in claim 6 wherein said doubleacting fluid motor means for effecting reciprocation of said plungermeans is controlled by a supply and exhaust valve means.

8. A concrete conveyor system as defined in claim 1 wherein said firstoperating means said second operating means and said means for effectingreciprocation of said plunger means are each independent double actingfluid motor means; a first supply and exhaust valve means forsimultaneously actuating the double acting fluid motor means associatedwith said inlet and said outlet and a second supply and exhaust valvefor actuating said double acting fluid motor means associated with saidplunger means.

9. A concrete conveyor system as defined in claim 1 wherein said meansfor effecting reciprocation of said plunger means, said first operatingmeans and said second operating means are fluid actuated means; at leastthe fluid actuated means for effecting reciprocation of the plungermeans includes a supply and exhaust conduit means for supplying andexhausting actuating fluid thereto and therefrom; said concrete conveyorsystem further including a concrete receiver hopper having a rotatablefeed screw means therein arranged for feeding concrete to `said inletmeans; a rotary fluid motor means arranged for the actuation of saidfeed screw means by fluid under pressure passing through said supply andexhaust conduit means; and a by-pass conduit means connecting saidsupply and exhaust conduit means downstream of said rotary fluid motormeans with a region of low pressure whereby operation of said feed screwmeans may continue after flow of actuating fluid to said fluid actuatedmeans for effecting reciprocation of said plunger means has beendiscontinued.

10. A concrete conveyor system as defined in claim 1 and furtherincluding hingedly connected plate means hingedly mounting said trapchamber with respect to said cylinder whereby said trap chamber andcylinder can be opened at the junction therebetween for cleaningthereof.

11. A concrete conveyor system comprising a concrete displacement meansincluding a concrete inlet means and a concrete outlet means; a firstfluid operated motor means associated with said concrete displacementmeans to effect operation thereof; a concrete receiver including a feedscrew for feeding concrete through said inlet means into saiddisplacement means; a main fluid conduit means for supplying operatingfluid to said first fluid operated motor means; a second fluid motormeans arranged to actuate said feed screw in response to the flow offluid through said main conduit means and a by-pass conduit meansleading from said main conduit means downstream of said second motormeans whereby operation of said second motor means may be continued eventhough flow of fluid through said main conduit means to said first fluidmotor means has been terminated.

12. A concrete conveyor system as deflnend in claim 11 wherein a dumphopper, provided with an opening in a wall thereof, is mounted to rotateabout an axis extending longituidnally of and above the inlet opening ofthe concrete receiver whereby the hopper may be rotated about its axisso as to locate the opening in the hopper in a position in whichconcrete may be introduced into said hopper through said opening or to aposition in which concrete may be discharged therethrough into saidconcrete mix receiver.

13. A concrete conveyor system as defined in claim 12 wherein said dumphopper is provided with an agitator means.

14. A concrete conveyor system as dened in claim 13 wherein saidadgitator means comprises a rotatably supported agitator shaft providedwith a plurality of paddles.

15. A concrete conveyor system as defined in claim 14 wherein saidrotary auger includes a rotatable shaft and means is provided to rotatesaid agitator shaft by said auger shaft.

16. A concrete conveyor system comprising a lsupport means; a concretedisplacement means mounted on said support means having an outletterminating in a first member having a iirst plate-like surface lying ina plane; a concrete receiver mounted above said concrete displacementmeans having a delivery outlet lying in the plane containing said firstplate-like surface; and a trap chamber unit, including a trap chambermeans having a second plate-like surface, mounted for pivotal movementinto and out of engagement with said rst plate-like surface and an openended inlet chamber movable simultaneously with said trap chamber meansinto and out of registration with said delivery outlet of said concretereceiver.

17. A concrete conveyor system for advancing concrete from a sourceofsupply to a location remote therefrom, and comprising:

(A) a concrete displacement means comprising:

(l) a trap chamber having an inlet;

(2) cylinder means disposed at one end of said trap chamber and incommunication therewith;

(3) plunger means slidably mounted in said cylinder means forreciprocation there-within; and

(4) means for effecting reciprocation of said plunger means;

(B) concrete mixing and supply means for supplying concrete to said trapcham-ber through said inlet;

(C) a hydraulically operable valve system for opening and closing saidinlet of said trap chamber and for opening and closing the path oftravel of material through said trap chamber; whereby when said inlet isopen, said path of travel can be closed, and when said path of travel isopen said inlet can be closed so that movement of said plunger means ina direction away from said trap chamber causes concrete to How throughsaid inlet in said 'trap chamber into said cylinder means while saidpath of travel is closed, and movement of said plunger means in adirection toward said trap chamber causes concrete to How therethroughwhile said inlet is closed.

18. A concrete conveyor system as defined in claim 17 and furtherincluding hingedly connected plate means hingedly mounting said trapchamber with respect to said cylinder whereby said trap chamber andcylinder can be opened at the junction therebetween for cleaningthereof.

19. A concrete conveyor system for advancing concrete from a source ofsupply to a selected locating comprising a concrete displacement meanshaving an inlet means and an outlet means; a concrete receiver chamberfor supplying concrete to the inlet of said displacement means, saidreceiver chamber including a rst opening in communication with saiddisplacement means, a lateral second concrete admission opening forcommunication with a source of concrete and a third atmospheric openinglocated outwardly of said iirst and second openings; and an outwardlyopening check valve means disposed outwardly of said iirst and secondopenings and inwardly of said third opening arranged to substantiallypreclude the admission of air through said receiver chamber into saiddisplacement means `during a suction operation of said displacementmeans.

References Cited UNITED STATES PATENTS 778,878 l/1905 Moir 259-1692,131,681 9/1938 Ball 259-l69 2,649,289 8/1953 Giberson 259-270 X ROBERTW. JENKINS, Primary Examiner U.S. C1. X.R. 198--226

